This invention relates generally to a portable electric humidifier and, more particularly, to a portable electric humidifier with an automatically de-energized removable humidification unit.
Portable humidifiers are used commonly to enhance environmental conditions in residential and commercial buildings. One well known type of humidifier employs a liquid supply tank and a humidification unit both removably mounted on a base that defines a reservoir. The humidification unit includes an electrically energized heater coil that projects into the reservoir so as to induce dispersion of liquid retained therein. Cleaning of the base and reservoir is facilitated by removal of the tank and humidification unit from the base. Also known (U.S. Pat. No. 5,014,338) is a portable humidifier having a humidification unit hinged to a base and pivotable into a position that provides access to a reservoir.
Various safety hazards are created by displacement of a liquid supply tank or an electrically energized humidification unit from a proper operating position on a base, particularly a unit having an exposed heater coil. Those problems are addressed in U.S. Pat. No. 5,133,044 which discloses a system for automatically de-energizing a heater coil in response to relative movement between a base and a humidification unit retained thereby, and U.S. Pat. No. 5,131,070 which discloses a humidification unit that is automatically de-energized in response to removal of a supply tank from a base. Included in the first disclosed system is an electrical switch mounted in the humidification unit and operated by an actuator mounted in the base. Also known is a portable humidifier which attempts to prevent unsafe operation by utilizing a power cord and passes through a window in a base and connects to a removable humidification unit. However, by drawing the still connected power cord through the window in the base as the unit is removed, unsafe continued energization of the unit can occur.
The object of this invention, therefore, is to provide an improved portable humidifier in which unsafe operation is prevented.